Design and construction for major treatment plant

Annacis Island Wastewater Treatment Plant (AIWWTP) is the largest secondary treatment plant in British Columbia and serves about a million people.

This is a full scale pilot facility to allow Metro Vancouver to receive and test a variety of digestible organic wastes, monitor the feed rates and measure the effects of these feedstocks on the performance of the digesters.

Feed stocks include:

Fats, oil, greases (FOG) from West Cost Reduction (WCR)

Dissolved air flotation thickener (DAFT) float

Thickened primary sludge (TPS) from the other WWTPs of Metro Vancouver

Off-spec milk

Glycerol from biodiesel production and spent de-icing fluid

The facility is also capable of receiving and screening thickened sludge hauled from other wastewater treatment plants, providing relief to manage digester upsets at other sites.

We designed the codigestion facility to handle average delivery of five truckloads per day; unload truckloads of 5000 L each, with occasional 20,000 L TPS truckloads; and with pumping capacity of 3 L/s (260m3/d) to feed the digesters.